Linear and Nonlinear Optical Properties of Natural Dyes Freestanding Films and Application in Optical Limiting

Abstract

Natural dyes were followed and prepared from a pomegranate, purple carrot, and eggplant peel.  The absorbance spectra was measured in the wavelength range 300-800 nm. The linear properties measurements of the prepared natural dye freestanding films were determined include absorption coefficient (α₀), extinction coefficient (κ), and linear refraction index (n). The nonlinear refractive index n₂ and nonlinear absorption coefficient β₂ of the natural dyes in the water solution were measured by the optical z-scan technique under a pumped solid state laser at a laser wavelength of 532 nm. The results indicated that the pomegranate dye can be promising candidates for optical limiting applications with significantly low optical limiting of 3.5 mW.